1. Field of the Invention
The present invention relates to a reciprocating compressor, and more particularly, to a reciprocating compressor that is capable of minimizing a loss of driving force, reducing noise occurrence, simplifying a structure and heightening a precision of assembly.
2. Description of the Background Art
In general, a refrigerating cycle unit is formed as a compressor, a condenser, expansion unit and evaporator, and the like, are sequentially connected by a connecting tube.
Among them, the compressor sucks and discharges a refrigerant gas. Depending on the method for compressing gas, there are various types of compressors including a rotary compressor, a reciprocating compressor and a scroll compressor, etc.
The compressor includes a closed container having an internal space, an electric mechanism part mounted in the closed container and generating a driving force, and a compression mechanism part compressing gas upon receiving the driving force of the electric mechanism part.
As shown in FIG. 1, in the rotary compressor, as a rotor 2 of the electric mechanism part (M) mounted in the closed container 1 is rotated, a rotational shaft 3 press-fit in the rotor 2 is rotated.
According to the rotation of the rotational shaft 3, in a state that a rolling piston 5 inserted in an eccentric portion 3a of the rotational shaft 3 positioned in the compression space (P) of the cylinder 4 is linearly in contact with a vane which is inserted at the inner circumferential surface of a compression space (P) of the cylinder 4 and one side of a cylinder 4, dividing the compression space (P) into a high pressure portion and a low pressure portion, the rolling piston 5 is rotated inside the compression space (P) of the cylinder 4.
In the rotation process, a series of processes in which the refrigerant gas is introduced into a suction hole 4a formed at one side of the cylinder 4, compressed in the compression space (P) and discharged through a discharge hole 4b positioned at one side of the compressor are repeatedly performed.
With reference to FIG. 2, in the reciprocating compressor, a rotor 12 of the electric mechanism part (M) mounted in the closed container 11 is rotated, a crank shaft 13 press-fit in the rotor 12 is rotated. As the crank shaft 13 is rotated, a piston 14 coupled to an eccentric portion 13a of the crank shaft 13 is linearly moved in the compression space (P) of the cylinder 14, compressing refrigerant gas sucked through a valve assembly 16 coupled to the cylinder 15, and at the same time, discharging the gas through the valve assembly 16, and this process is repeatedly performed.
With reference to FIG. 3, in the scroll compressor, as a rotor 22 of an electric mechanism part (M) mounted in a closed container 21 is rotated, a rotational shaft 23 provided with an eccentric part 23a press-fit at the rotor 22 is rotated.
According to the rotation of the rotational shaft 23, a revolving scroll 24 coupled to the eccentric portion 23a of the rotational shaft 23 is engaged with a fixed scroll 25 and makes a revolving movement, according to which a plurality of compression pockets formed by wraps 24a and 25a in an involute curve form respectively formed at the revolving scroll 24 and the fixed scroll 25 are made small, thereby successively sucking, compressing and discharging refrigerant gas. This process is repeatedly performed.
Problems of the rotary compressor, the reciprocating compressor and the scroll compressor operated in each compression mechanism will now be described in its structural aspect, performance aspect and reliability aspect.
First, the rotary compressor will now be described.
Referring to its structural aspect, the rolling piston 5 press-fit at the rotational shaft 3 having the eccentric portion 3a and at the eccentric portion 3a and a plurality of balance weights 6 coupled to the rotor 2 for a rotational balance of the eccentric portion 3 are used. Thus, as the parts are increased in number, its construction is complicated. In addition, since the sliding contact portion is wide, oil use amount is increased.
Referring to its performance, since the eccentric portion 3a of the rotational shaft 3 and the rolling piston 5 inserted into the eccentric portion 3a are positioned inside the compression space (P) of the cylinder 4, the compression volume is small compared to the compression mechanism part. In addition, when the rotational shaft 3 is rotated once, compression stroke is made by one time, so that the compression performance is low. Moreover, since a rotational torque becomes large as the plurality of balance weights 6 are attached, the loss of power is large.
Referring to its reliability, the eccentric portion 3a formed at the rotational shaft 3 and the rolling piston 5 are eccentrically rotated, so that a vibration noise is generated during the rotation.
Secondly, the reciprocating compressor will now be described.
Referring to its structural aspect, the crank shaft 13 provided with the eccentric portion 13a, the piston 14 coupled to the crank shaft 13 and the balance weight 13b for a rotational balance with the eccentric portion 13a formed at the crank shaft 13 are used. Thus, the number of parts is increased to complicate its structure. In addition, since the sliding contact area between the piston 14 and the cylinder 15 is wide, so that more oil is to be used.
Referring to its performance, the piston 14 compresses gas while being reciprocally moved in the compression space (P) formed in the cylinder 15, the compression discharge amount can be somewhat increased when the crank shaft 13 is rotated one time. But since one time of compression stroke is made for one time of rotation of the crank shaft 13, it""s also inefficient. In addition, since the rotation torque becomes large by the eccentric portion 13a of the crank shaft 13 and the balance weight 13b, a loss in the driving power is large.
Referring to its reliability, since the eccentric portion 13a formed at the crank shaft 13 is eccentrically rotated, a vibration noise is generated. Also, since the valve assembly 16 is operated in sucking and discharging gas, the sucking/discharging noise is loud.
Lastly, the scroll compressor will now be described.
Referring to its structural aspect, since the rotational shaft 23 having the eccentric portion 23a, the revolving scroll 24 having the wraps in an involute curve form, and the balance weight 26 for a rotation balance of the fixing scroll 25 and the eccentric portion 23a are used, the parts are increased in number and its construction is complicated. In addition, processing of the revolving scroll 24 and the fixing scroll 25 is very difficult.
Referring to its performance and reliability, the plurality of compression pockets formed by the wrap 24a of the revolving scroll 24 and the wrap 25a of the fixing scroll 25 continuously compresses the refrigerant gas. Thus, the compression performance is desirable, but a vibration noise is generated due to the revolving movement of the revolving scroll and the eccentric movement appearing at the eccentric portion 23a formed at the rotational shaft 23.
Therefore, an object of the present invention is to provide a reciprocating compressor that is capable of minimizing a loss of driving force, reducing noise occurrence, simplifying a structure and heightening a precision of assembly.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a reciprocating compressor including: a closed container having a suction tube and a discharge tube connected thereto; a reference frame elastically supported and mounted in the closed container; a driving motor mounted at one side of the reference frame and generating a linear reciprocating driving force; a front frame coupled to the other side of the reference frame and having a cylinder insertion hole therein; a cylinder inserted into the cylinder insertion hole formed at a central portion of the front frame; a piston inserted in the cylinder to suck, compress and discharge a refrigerant gas; a connection type magnet holder positioned penetrating the reference frame; an engaging portion engaging the connection type magnet holder and the piston; a discharge valve assembly coupled to cover a compression space formed inside the cylinder and discharging gas; a spring position at both sides of the piston and elastically supporting a motion of the piston; and a suction valve coupled at an end portion of the piston and switching a refrigerant suction passage.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.